apropos

apropos linux command cheatsheet by Thamizhiniyan C S

Introduction

The apropos command is used to search the manual page names and descriptions.

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Syntax

apropos [-dalv?V] [-e|-w|-r] [-s list] [-m system[,...]] [-M path] [-L locale] [-C file] keyword ...

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Important Flags

Flag	Description
whatis -d, --debug	Prints debugging messages.
whatis -v, --verbose	Print verbose warning messages.
whatis -e, --exact	Search each keyword for exact match.
whatis -r, --regex	Interpret each keyword as a regex.
whatis -w, --wildcard	The keyword(s) contain wildcards.
whatis -a, --and	Require all keywords to match.
whatis -l, --long	Do not trim output to terminal width.
whatis -C, --config-file=FILE	Uses user-configuration files instead of the $MANPATH.
whatis -L, --locale=LOCALE	Define the locale for this search.
whatis -m, --systems=SYSTEM	Use manual pages from other systems. Looks for man page descriptions from other OSs.
whatis -M, --manpath=PATH	Sets the search path to PATH rather than the default $MANPATH.
whatis -s, --sections=LIST, --section=LIST	Search only these sections (colon-separated). Searches only in specific man pages sections.
whatis -?, --help	Give this help list.
whatis --usage	Give a short usage message.
whatis -V, --version	Print program version.

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Examples

Command	Description
apropos list	The apropos primary usage is to find a single keyword in man pages.
apropos -a list directory	Add another variable to narrow down the matches.
apropos "list directory"	Achieve a similar effect without `-a` by encasing keywords in double quotes.
apropos delete terminate remove	Find Either of Two / More Parameters
apropos -e set	Find Exact Match
apropos -s 1,8 list	Search Specific Sections
apropos '^list'	Use Regex Symbols
apropos "zip(note|cloak|info)"	Use regex to conduct an even more specific search.
apropos -a -s 3,8 "^list" "(implementation|devices|users)"	As the output shows, each line includes list at the beginning, belongs to section 3 or 8, and has one of the keywords.
apropos list -l	To avoid the trimming of descriptions in apropos command output